Process for pyrolytic conversion of petroleum oils



Feb. 28, 1933. F A HOWARD 1,899,895

PROCESS FOR PYROLYTIO CONVERSION OF PETROLEUM OILS Filed June 29, 1927 OAKING DRUM SOA KING .DRUM

E E: E i? 12 FGS ^50.4K ING DR UM vwemtoi FRANK ,4.Ho WA RD.

Patented Feb. 28, 1933 FRANK A. HOWARD,. OF ELZABETH, NEW JERSEY, ASSIGNOR TO STANDARD OIL DEVELOPMENT COMPANY,`A CORPORATION OF DELAWARE PROCESS FOR PYROLYTIC CONVERSION OIF PETROLEUM OILS Application led .Tune 29,

This invention relates to the cracking of petroleum oils in equipment comprising a heating conduit discharging into a thermally insulated digesting chamber or soaking drum.

l have found that the conversion eiiciency oi such systems may be materially increased and the formation of troublesome carbonaceous deposits in the drum 4decreased by maintaininga local circulation in the drum.

The inventiony will be fully understood from the lfollowing description, read in connection with the accompanying drawing, in which:

Fig. l is a diagrammatic vertical section through equipment suitable for carrying out my method, and;

Figs. Qand 3 are views similar to 1. showing alternative forms of the equipment.

Reference numeral l in each ligure desigantes a firebrick setting heated by any suitable means. Fresh oil is supplied through inlet pipe 2 to heating conduit 3, Which kconsists preferably of a series of tubes joined end to endby crossover connections to form a continuous circuit. Heating conduit 3 discharges through pipe 4 into digesting chamber or soaking drum 5 surrounded by thermal insulation 6. 7 is a line for the con-` tinuous Withdrawal ot the cracked product. A pressure control valve 7 is installed in this line. The cracked product is fractionated and condensed in any suitable Way. y

Referring particularly to Fig. l a pipe 8 communicates vvith the soaking drum 5 at a point near the top thereof. A pump 9 may be operated to continuously draw oil through pipe 8 into pipe l0, which in turn discharges into heating conduit 3.

Referring specifically. to Fig. 2, a rotatable propeller 11 `is attached to shaitt 12, actuated by motor 13. 14 is a stulling boX through which shaft l2 enters the drum and 15 is a draft tube to cause the material propelled to traverse a substantial part of the length ofthe drum to maintain the desiredcirculation. y,

Referring specilically to Fig. 3, a et 16 is arranged to discharge the heated materiall from conduit 3 into drum 5. 17 represents al 1927. Serial No. 202,191.

draft tube or pipe and 18 a Venturi throat which, however, may be dispensed With. This form of the invention is generally to be preferred.

The circulation of oil and/or oil vapor in the drum is l preferably continuous throughout the cracking period. Since methods oi` operating coil and drum installations kot the type described are Well known (except as to the local circulation in the drum), no description of such methods is required here. While l have described my invention in conjunction yvvith certain specic forms of apparatus, it Will be understood that it is not limited thereto but covers broadly any cracking system in which oils are caused to oW under pressure in a continuous stream through a heating Zone in Which they are yheated to cracking temperature andv are subsequently transferred to a soaking or digesting chamber in which the temperature is not raised and apositive local circulation of the contents of the chamber is maintained.

What I claim is:

The improvement in cracking which comprisestlowing a stream of the oil through an elongated narrow heating zone under conv. ditions to give substantial cracking, then through a thermally inslulated enlarged digestion zone in Which the oil is held for a relatively long time under cracking conditions, continuously abstracting oil from said digestion Zone, uniting such abstracted oil with said stream in the heating Zone at an intermediate point, heating the combined stream, returning the same to the digestion Zone, and continuously withdrawing all ot' the liuid products from the digestion Zone in a single stream. FRANK A HOWARD 

